The present technology relates to a display panel capable of improving an unlit defect, and to a display unit and an electronic apparatus that include the display panel.
In recent years, in the field of display units for image display, there have been developed and commercialized display units using, as a light emitting device of a pixel, a light emitting device of a current-driven type, such as an organic EL device, in which luminance is varied in accordance with the value of a current flowing therein. Unlike a liquid crystal device and the like, an organic EL device is a self-emitting device. Therefore, since display units (organic EL display units) using an organic EL device do not necessitate light source (backlight), such display units provide reduced thickness and higher luminance in comparison with liquid crystal display units that necessitate light source.
The driving scheme of organic EL display units includes a simple (passive) matrix scheme and an active matrix scheme as is the case with liquid crystal display units. The simple (passive) matrix scheme has a simple structure; however, there are issues such as that it is difficult to realize a large-size and high-definition display unit with the simple (passive) matrix scheme. Therefore, today, the active matrix scheme has been vigorously developed. Under this scheme, a current flowing through a light emitting device provided for each pixel is controlled by an active device (commonly, a TFT (thin film transistor)) provided in a driving circuit provided for each light emitting device.
Incidentally, an organic EL device has a structure in which an organic layer including a light emitting layer is interposed between an anode electrode and a cathode electrode. If a foreign substance enters an organic EL display unit using the organic EL device having the above-mentioned structure as a light emitting device of a pixel in a process of forming the organic EL device, then a luminance defect of the pixel occurs. Specifically, a short circuit may take place between an anode electrode and a cathode electrode of the organic EL device due to the entrance of the foreign substance in the organic EL in the manufacturing process. When this short circuit between electrodes of an organic EL device occurs, the organic EL ceases to emit light, thus causing a luminance defect that is a so-called “unlit spot” in which a sub pixel including this organic EL device is visually recognized as a non-light emitting pixel.
As a countermeasure against this luminance defect due to the entrance of a foreign substance, there has been proposed a technique in which a plurality of sets of component devices including an organic EL device are provided in one sub pixel (for example, see Japanese Unexamined Patent Application Publication No. 2007-41574). With this technology, even if an organic EL device in one of the sets becomes a defect due to a short circuit between electrodes or the like, a component device in another set normally operates to prevent the sub pixel from becoming the unlit spot.